Flavors Of Research In Physics

This compendium is earmarked for young inquisitive mind trying to comprehend and understand the different manifestations in the world around us from a scientific view point. The coverage in the book is a virtual rainbow covering the many shades of physics principles operating in nature, from the microcosm to macrocosm, the world of sub-atomic particles, the interactions of light and matter, the underlying forces in nature, our own environment, the Sun and the solar system and the universe at large, painted by people who are some of the renowned experts in their subject domain. Successful indigenous efforts towards development of novel techniques, outlined in the volume, should be an eye opener for those who would like to take up challenging tasks. Likewise, our lack of precise understanding of phenomena that we encounter routinely demonstrates how little we know the nature around us.

We have a long way to go before we can comprehend nature in all its beauty and complexities. This volume is intended to kindle enthusiasm amongst young people who are fascinated by nature and would like to understand the underlying scientific principles that govern all that we see, feel and experience around us.Happy reading!

Physics is the most fundamental of all branches of science. Its scope encompasses the extremely small (elementary particles) to the most gigantic (cosmos). Some basic principles and concepts of physics are simple and easy to follow while some others appear strange and complex. All the same, they are exciting. Flavors of Research in Physics seeks to convey this excitement, successfully in my view, to young minds. I congratulate the Ahmedabad Local Chapter of the Indian National Science Academy and Utpal Sarkar in particular, for producing this book. I thank all my colleagues who have contributed different articles for their wonderful effort. I am sure the young readers would find the book as interesting as I did when I quickly browsed through the manuscript.

What is research in Physics? This was a question asked by a couple of school students during their visit to our Laboratory. I tried to explain to them by saying that we try to understand our nature in terms of some simple laws and then see how we can make use of our knowledge to improve our living. But the students were not satisfied. Their teachers can explain whatever questions they ask about nature, so if they want to take up research in Physics as their career, will there be anything left for them to do? In other words, what are the actual challenging problems in physics at present? These questions baffled me for some time and then I envisioned the idea of bringing out a compendium that may address such questions and led to this volume.

It is not possible to cover all the research areas in physics within the premises of this small volume, so we had to restrict ourselves to some of the more fascinating modern research topics only and approached experts in the relevant field who are also fellow of INSA to contribute to this volume. Some of the eminent experts were, most understandably, quite busy at this point of time and we could not include a few of these exciting topics we initially wanted to have. We hope to include them in the next edition of this volume.

Having said this let us move on to the exciting topics that this volume covers. One of the most important questions pertaining to nature is what are the building blocks of our physical world? Our present knowledge reveals that there are four fundamental forces in nature: Gravitational, Strong, Weak and Electromagnetic. However, at higher energies some of these forces could get unified, like the unification of the electric and magnetic interactions. Some of the articles in this volume discuss these developments and describe how their interconnection can be traced to the evolution of our universe. The other articles describe how we use our technology to understand our nature, beyond what our senses could reveal. We also need to understand the varieties of complex systems and find simple laws to explain them and provide an unified picture of all the diverse fields. Moreover, the volume includes some modern developments in laser physics, fusion reactors, developments in microwaves and radio astronomy, solar physics and space missions including our recent Moon mission. It is fascinating to know that the techniques we use to find out about dinosaurs, are also being used to find out how the climate has been changing from the time of the dinosaurs to the present or to learn about the origin of the solar system from studies of the meteorites. Since the topics covered are so widely different, we present the articles in accordance with the alphabetical ordering of the author names. Editorial interferences were kept to a minimum in order to keep the personal perspectives of the authors intact in these articles, and the articles remain self explanatory.

It is an extremely difficult task to explain these advanced research topics to students, so only the real masters of the subject can attempt to reach out to the students and take up this challenge. On the other hand, these experts are all too busy with their work. Thus, initially I was assailed by a certain amount of trepidation. But to my surprise I found that most of the physicists I approached supported my venture profusely and generously agreed to contribute to this volume. Some of our colleagues could not make it within the time frame we set for this volume, but they provided moral support and encouraged me to proceed with the volume. I am extremely thankful to all of them. I am particularly indebted to the contributors, who made this volume a reality and I appreciate their sincere efforts to provide a lucid exposition of such difficult research topics for non-specialists.

This volume has been published under the auspices of the Indian National Science Academy (INSA), New Delhi, by the Ahmedabad local chapter (for the state of Gujarat and Rajasthan) and all of us associated with this volume take this opportunity to thank the INSA, New Delhi for it's support. We are particularly thankful to Prof. M. Vijayan, President, INSA, Prof. A.K. Sood, Vice-President, INSA and Prof. S.C. Lakhotia, Chairman, Science Education Program, INSA, for their support. Most of the outreach programs of the Ahmedabad local chapter of INSA are co-sponsored by the Physical Research Laboratory (PRL), Ahmedabad and I thank Prof. J.N. Goswami, Director, PRL for his continuing support towards these activities. Finally, we thank the young readers of this volume for the time they have devoted to go through this volume. We hope that this small effort of ours will inspire their curious mind to delve into the deeper mysteries of nature.

**Contents and Sample Pages**